Electric heating plate



A. mmm

ELEGTHIC HETINQ- PLATE Aug. 21, 1923.

mea sept. -6. 1922 L L I Emma Augrfzl, 1923.

UNITED 7 STATES l-'na'rENT OFFICE.

` ALFRED mmsm, or Hovnr, NEAR cnms'rrmm, NORWAY.

ELECTRIC HEATING PLATE.

Wannen mea september 6,/1922. seria; no. 586,501

' Wire type, in which the heating wire or spiral is placed Without protectlon on insulating material have the drawback, that overboil and spillage from the cooking vessel will' soil the heating wire and stick to it in torrefyinr and carbonizing. These substancescan tbe removed mechanically only at'the risk of hurting the heating wires. To clean thewire by burning off the fouling substancesis wearisome and also annoying due to the had smell emitted. Moreover the repeated annealing of the heating wire in contact with earbo'nizing substances vv ill have a very harmful effect upon the wire and shorten its life.

By the present invention these incon veniences are avoided, as it is possible to prevent the spillage from the cooking vessel from reaching the heating wire, and at the same time the heat from the incandescent Wire is utilized practically to the same extent as in the heating plates of the open wire type hitherto in us The invention is illustrated in the annexed drawings, in which- Fig. 1 represents a side elevation and vertical section through one half of the heating plate on the line c--w of Fig. 2,

Fig. a top view of the apparatus, the covering plate being removed, and I Fig. 3 a second vertical section on the line ai-g/ of Fig. 2 and therefore at a right angle with the section shown in Fig. 1.` i

The heatinfr wire B is arranged in suitable grooves termed in a bed E of tire-proof insulating material.

Grooves or channels I are formed in bed E between the grooves and in the bottoms of the grooves, slots A are preferably formed at intervals the object of which will be hereinafter explained. Above the hcating Wires and at some distance from the same a perforated plate lfl of: iron or other metal is provided. ou which the cookingvesscl is to be placed. The irietal plate has the shape oi' a grate, the bars F of which are situated above the heating Wires or spirals thus sheltering the latter, while the openings G of the grate correspond with the rooves in the insulating bed of the heating wires.

If some substance is spilt from the cooking vessel on the grate, this substance will not reach thek heating wires but pass down through the slots in the insulating` material to the bottom plate of the paratus, from where it may be removed. n order to fa cilitate this removal it is convenient to make the bottom plate detachable. Mostr ade quately it is given the shape of a drawer, that is easily pulled. out for cleaning and then replaced.

In order to prevent 'the heating spirals from coming into contact'with the'` plate H above them, small insulating pieces D for instance of mica are' inserted between the j plate H and the wire. These insulatino' pieces may be attached either to the late orto the insulating bed of the spira Instead of forming the grooves l in' the bed alud the slots A in the bottoms of vthe grooves', the heating coils or wires may be mounted in separate .tireproof "insulating bars spaced apart to form open chan-nels to permit the spillage to pass directly to the botto]y plate C. ln the structure shown the spillage collects in the channels and may be scraped away without injuring the heating wire.

The latter embodiment .has the advantage, that the bottom plate is better protected a ainst the heaty and likewise that the airraught through the apparatus is i easier to reguiate.

From the preceding it will be evident, that b the arrangement above described the soi ing of the apparatus andthe inconviences connected therewith are avoided, and these advantages are obtained Without relinquishing to any considerable extent the principle of the open wire syst in of heat transfer by direct radiation from the heating Wires to the cookingwessel. Through the openings G- the vessel receives the greatest part of the heat by direct radiation,

y and Where the heat rays do not inside direct on the cooking-vessel, the heat is absorbed by the bars F, and transferred to the vessel. It is understood that the invention vis not confined to any Teculiar disposition of the heating wire. e invention being appli cable with parallel arrangement of the ica' aeating' xvii-es Woll as with an arrangement in spirals 0:' in' o'ncentiie rings 0f :said wires.

l claim;

l. An electric heater comprising-a heatingwiie, an insulating support for the latter arranged to form spaces between poi'- tions ofthe wire, and a cover plate mounted above the latter and having; openings corresponglirm to said spaces.

Q Qiiuelectric beater, complisin, y a body of insulatingniaterial forming a sexies o channels, bare heating wires mounted on the insulating material parallel to the channels, a cover plate mounted above the insulating jmaterial and having openings therein above vlthe channels, and a, bottom plate mounted below the insulating material. 1

3. An electric heater, comprising a limi? 4of insulating .material having a series of vGrooves fomeol therein7 bare heating.; wires mounted in the ooi/em ehani'iels ioi'inetl in the insulating material between. the wires, and a coverplate mounted. above the latte? and having openings Corresponding to the channels.

A 4. An electifie heater, compi'ising bare heating wires, e boei of insulating material having grooves in which the wires are mounted, channels formed in the bed, be- 

